Make new feedback to be added as a new section to the end of the page (#5753)

* feedback: add the feedback as a new section at end of the page

Addresses feedback on #5542. For auto-archiving of section
to work properly on our feedback page, the new sections need to
be created at the end of the page rather than at the top.

So, adjust the feedback addition logic to make it such that the
feedback is appended to the bottom of the page.

* Replace lambda with a method reference

* feedback: replace edit summary with something more relevant

The summary of the feedback page was unhelpful. Make it more helpful by
using a more helpful summary that at least mentions the version of the
app for which the feedback is posted.

* test: try to fix test case related to feedback change

app/src/main/java/fr/free/nrw/commons/actions/PageEditClient.kt

@@ -78,6 +78,28 @@ class PageEditClient(
     }
 
 
+    /**
+     * Appends a new section to the wiki page
+     * @param pageTitle   Title of the page to edit
+     * @param sectionTitle Title of the new section that needs to be created
+     * @param sectionText  The page content that is to be added to the section
+     * @param summary     Edit summary
+     * @return whether the edit was successful
+     */
+    fun createNewSection(pageTitle: String, sectionTitle: String, sectionText: String, summary: String): Observable<Boolean> {
+        return try {
+            pageEditInterface.postNewSection(pageTitle, summary, sectionTitle, sectionText, csrfTokenClient.getTokenBlocking())
+                .map { editResponse -> editResponse.edit()!!.editSucceeded() }
+        } catch (throwable: Throwable) {
+            if (throwable is InvalidLoginTokenException) {
+                throw throwable
+            } else {
+                Observable.just(false)
+            }
+        }
+    }
+
+
     /**
      * Set new labels to Wikibase server of commons
      * @param summary   Edit summary

app/src/main/java/fr/free/nrw/commons/actions/PageEditInterface.kt

@@ -74,6 +74,16 @@ interface PageEditInterface {
         @Field("token") token: String
     ): Observable<Edit>
 
+    @FormUrlEncoded
+    @Headers("Cache-Control: no-cache")
+    @POST(MW_API_PREFIX + "action=edit&section=new")
+    fun postNewSection(
+        @Field("title") title: String,
+        @Field("summary") summary: String,
+        @Field("sectiontitle") sectionTitle: String,
+        @Field("text") sectionText: String,
+        @Field("token") token: String
+    ): Observable<Edit>
 
     @FormUrlEncoded
     @Headers("Cache-Control: no-cache")